Technical Field
[0001] The present invention relates to a medicament useful for treating and/or preventing
a sleep disorder. More specifically, the present invention relates to a medicament
containing an ORL-1 receptor agonist which is useful for treating and/or preventing
a sleep disorder, for example, a circadian rhythm sleep disorder such as jet-lag syndromes,
a shift-work sleep disorder, delayed sleep phase syndromes or the like.
Background Art
[0002] An ORL-1 (opioid receptor-like 1) receptor (FEBS Lett. 347, 284-288, 1994, FEBS Lett.
341, 33-38, 1994) was found to be a fourth opioid receptor next to δ, κ and µ receptors
in 1994. The ORL-1 receptor has about 60% homology of amino acid sequences with other
opioid receptors, but it is clearly distinguished from other opioid receptors in that
naloxone, a non-selective opioid receptor antagonist, does not bind thereto (FEBS
Lett. 341, 33-38, 1994). The ORL-1 receptor is mainly distributed in a central nerve
system broadly, and is expressed in high density especially in a cerebral cortex,
hippocampus, hypothalamus, amygdala and spinal cord, though it is also expressed in
peripheral organs such as intestine and spleen (Eur. J. Pharmacol. 340, 1-15, 1997,
Pharmacol. Rev. 53, 381-415, 2001).
[0003] Endogenous ligands for the ORL-1 receptor were identified successively by the research
groups in France and Switzerland in 1995, and were designated as nociceptin (Nature
377, 532-535, 1995) and orphanin FQ (Science 270, 792-794, 1995), respectively. Nociceptin
has been reported to be a peptide consisting of 17 amino acids, and plays a critical
role in central functions such as learning, memory, anxiety and stress (Br. J. Pharmacol.
129, 1261-1283, 2000).
[0004] Specifically, it has been reported that injecting a small amount of nociceptin to
hippocampus of rats causes learning disorder in water-maze learning test (Eur. J.
Neurosci. 9, 194-197, 1997) and the nociceptin receptor knock-out mice are quick in
learning acquisition in water-maze learning test as compared to normal mice (wild-type),
and that long term potentiation (LTP) in hippocampus of knock-out mouse is enhanced
as compared to normal mice (Nature 394, 577-581, 1998). Nociceptin is considered to
inhibit memory and/or learning functions. In addition, it has been reported that if
nociceptin is administered intraventricularly in rats, the anti-anxiety activity is
found to be almost equivalent to diazepam in a behavioral pharmacology test such as
a conflict test, a light-dark box test and an elevated plus maze test (Proc. Natl.
Acad. Sci. USA 94, 14854-14858, 1997). Further, it has been reported that the sensitivity
to stress is enhanced, and the adaptation ability to stress is inhibited in nociceptin
knock-out mice as compared to normal mice (Proc. Natl. Acad. Sci. USA 96, 10444-10449,
1999). In other words, nociceptin is considered to have a defensive physiological
action against anxiety or stress, and the ORL-1 receptor agonist is likely to show
anti-anxiety actions by a completely different mechanism from benzodiazepine compounds.
[0005] From the above, it has been reported that a compound having an agonistic and/or antagonistic
activity for the ORL-1 receptor, is useful for treating a mental disorder, a neural
disorder and a physiological disorder, and in particular for improving anxiety and
stress disorders, depression, a trauma disorder, memory loss from Alzheimer's disease
or other dementia, epilepsy and spasm symptoms, acute and/or chronic pain symptoms,
withdrawal symptoms from drug addiction, control of water balance, Na
+ excretion, arterial blood pressure disorder and eating disorder such as obesity and
anorexia (publications such as JP-A-2000-26466, JP-A-11-228575, JP-A-10-212290, JP-A-2000-53686,
WO00/14067, WO99/29696, EP1122257, JP-A-2001-39974, WO00/08013, WO99/36421, EP0997464,
WO03/000677, WO98/54168, WO00/31061, JP-A-2001-58991, WO01/39767, WO01/39775, WO02/085291,
WO02/085354, WO02/085355, WO02/085361, WO00/27815, WO00/06545, WO99/59997, WO99/48492,
WO02/26714, etc.).
[0006] On the other hand, the circadian rhythm sleep disorder is a disease in which a person's
main complaint or cardinal symptom is the lack of normal sleep at night, and this
disease may sometimes disturb ordinary social behavior. This disease includes a variety
of pathological states, for example, endogenous chronic syndromes such as delayed
sleep phase syndromes caused by a disruption of the biological clock and its synchronizing
mechanism, as well as exogenous acute syndromes such as jet-lag syndromes and a shift-work
sleep disorder. Although various drug therapies have been tried for the treatment
of circadian rhythm sleep disorder, it has been revealed that only an insufficient
therapeutic effect can be obtained with hypnotics, which are typically benzodiazepine
hypnotics (as a Review of pathologic states, therapy or others for a circadian rhythm
sleep disorder, see, for example, S. Ozaki and K. Okawa, "Sleep Disorder and Biological
Rhythm", Special feature; Chronopharmacology, New Guideline of Administration, Molecular
Medicine, Vol.34(3), pp. 355-365, 1997, etc.).
[0007] Entrainment factors of circadian rhythm are classified into the two major groups
of light (photic entrainment) and other factors than light (non-photic entrainment).
The drugs which have been known to cause non-photic entrainment so far, are serotonin
agonists, benzodiazepine hypnotics, melatonin and the like, but no ORL-1 receptor
agonist has been reported to cause non-photic entrainment. One paper has disclosed
that a small amount of nociceptin, an endogenous ligand of the ORL-1 receptor, was
injected into suprachiasmatic nucleus, biological clock of hamster, but the paper
has concluded that nociceptin inhibits photic entrainment, but nociceptin itself does
not cause non-photic entrainment (J. Neurosci., Vol.19(6), pp. 2152-2160, 1999).
[0008] In addition, the above-mentioned publications and the patent publication neither
disclose nor suggest that a compound having an agonistic and/or antagonistic activity
for the ORL-1 receptor, can be used for treating a circadian rhythm sleep disorder.
Disclosure of the Invention
[0009] As described above, the relation of the ORL-1 receptor and the circadian rhythm has
not been fully clarified, but the present inventors have found unexpectedly that a
compound having an affinity for the ORL-1 receptor, in particular a compound acting
on the ORL-1 receptor as an agonist, acts as a non-photic entrainment factor, and
advances the circadian rhythm phase. In other words, the present inventors have made
extensive researches with the purpose of developing a novel therapeutic agent for
circadian rhythm sleep disorder, and have found that ORL-1 receptor agonist can be
a preventive and/or therapeutic agent for a sleep disorder including the circadian
rhythm sleep disorder, which resulted in the completion of the present invention.
[0010] The present invention relates to a medicament useful for treating and/or preventing
a sleep disorder. More specifically, the present invention provides a medicament containing
an ORL-1 receptor agonist which is useful for preventing and/or treating a sleep disorder,
for example, a circadian rhythm sleep disorder such as jet-lag syndromes, a shift-work
sleep disorder, or delayed sleep phase syndromes, and a novel compound having an ORL-1
receptor agonist action.
[0011] Specifically, the present invention provides the following.
1. A preventive and/or therapeutic agent for a sleep disorder containing an ORL-1
receptor agonist.
2. A preventive and/or therapeutic agent for a sleep disorder comprising a therapeutically
effective amount of an ORL-1 receptor agonist and pharmaceutically acceptable additives.
3. The preventive and/or therapeutic agent as described in the above-mentioned 1 or
2, wherein the sleep disorder is a circadian rhythm sleep disorder.
4. The preventive and/or therapeutic agent as described in the above-mentioned 3,
wherein the circadian rhythm sleep disorder is a jet-lag syndrome.
5. The preventive and/or therapeutic agent as described in the above-mentioned 3,
wherein the circadian rhythm sleep disorder is shift-work sleep disorder.
6. The preventive and/or therapeutic agent as described in the above-mentioned 3,
wherein the circadian rhythm sleep disorder is a delayed sleep phase syndrome.
7. The preventive and/or therapeutic agent as described in the above-mentioned 1 or
2, used for preventing and/or treating the symptoms involved in a geriatric circadian
rhythm sleep disorder.
8. The preventive and/or therapeutic agent as described in the above-mentioned 1 or
2, used for bright light therapy.
9. The preventive and/or therapeutic agent as described in the above-mentioned 1 or
2, wherein the ORL-1 receptor agonist has an affinity of 1000 nmol/L or less IC50 value for the ORL-1 receptor, and further inhibits CAMP elevation caused by a CAMP
inducer by 50% or more at a concentration of 1000 nmol/L or less.
10. A compound represented by the formula (I)

wherein
R1 is
(1) hydrogen,
(2) lower alkyl,
(3) lower alkenyl,
(4) -C(O)-lower alkyl,
(5) -C(O)O-lower alkyl,
(6) -C(O)-phenyl (the phenyl group may be substituted with lower alkyl, halogen, lower
alkoxy, phenoxy or benzyloxy),
(7) lower alkyl-carboxyl,
(8) lower alkyl-C(O)-phenyl (the phenyl group may be substituted with lower alkyl,
halogen, lower alkoxy, phenoxy or benzyloxy) ,
(9) lower alkyl-C(O)O-lower alkyl,
(10) lower alkenyl-C(O)O-lower alkyl,
(11) lower alkyl-O-lower alkyl,
(12) lower alkyl-C(O)NR3R4,
(13) -S(O) 2-lower alkyl,
(14) -S(O)2-phenyl (the phenyl group may be substituted with lower alkyl, halogen, lower alkoxy,
phenoxy or benzyloxy),
(15) lower alkyl-S-lower alkyl,
(16) lower alkyl-S(O)-lower alkyl,
(17) lower alkyl-S(O)2-lower alkyl,
(18) lower alkyl-S (O)2NR3R4,
(19) phenyl (the phenyl group may be substituted with lower alkyl, halogen, lower
alkoxy, phenoxy or benzyloxy), or
(20) benzyl (the phenyl group may be substituted with lower alkyl, halogen, lower
alkoxy, phenoxy or benzyloxy),
R2 is hydrogen, lower alkyl, halogen, lower alkoxy, phenoxy, benzyloxy, trifluoromethyl,
nitro, amino or cyano,
R3 and R4
may be the same or different, and each is hydrogen, lower alkyl or lower alkenyl,
or R3 and R4 may bind with an adjacent nitrogen atom to form a saturated nitrogen-containing hetero
ring (the hetero ring may be substituted with lower alkyl, halogen, lower alkoxy,
phenoxy or benzyloxy), and
X is O or S.),
a racemic mixture thereof, an enantiomer corresponding thereto, or a pharmaceutically
acceptable salt thereof.
11. The compound as described in the above-mentioned 10, wherein R2 is hydrogen, and X is O.
12. The compound as described in the above-mentioned 10, wherein R1 is -C(O)-lower alkyl, lower alkyl-C(O)NR3R4 (either R3 or R4 is hydrogen) or lower alkyl-C(O)NR3R4 [R3 and R4 bind with an adjacent nitrogen atom to form a saturated nitrogen-containing hetero
ring (the hetero ring may be substituted with lower alkyl, halogen, lower alkoxy,
phenoxy or benzyloxy)].
13. The compound as described in the above-mentioned 10, which is selected from
(RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one,
(R)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one,
(S)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one,
(R)-3-acetyl-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one,
(R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}-N-methylacetamide,
and
(R)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-3-(2-oxo-2-piperazin-1-ylethyl)-1,3-dihydro-2H-benzoimidazol-2-one.
14. The preventive and/or therapeutic agent as described in the above-mentioned 1
or 2, wherein the ORL-1 receptor agonist is a compound represented by the formula
(I)

wherein each symbol is as defined above, a racemic mixture thereof, an enantiomer
corresponding thereto, or a pharmaceutically acceptable salt thereof.
15. A method of preventing and/or treating a sleep disorder, comprising administering
an effective amount of an ORL-1 receptor agonist to the patients.
16. The method as described in the above-mentioned 15, wherein the ORL-1 receptor
agonist has an affinity of 1000 nmol/L or less IC50 value for ORL-1 receptor, and further inhibits CAMP elevation caused by a CAMP inducer
by 50% or more at a concentration of 1000 nmol/L or less.
17. The method as described in the above-mentioned 15, wherein the ORL-1 receptor
agonist is a compound represented by the formula (I)

wherein each symbol is as defined above, a racemic mixture thereof, an enantiomer
corresponding thereto, or a pharmaceutically acceptable salt thereof.
18. Use of an ORL-1 receptor agonist for manufacturing a preventive and/or therapeutic
agent for a sleep disorder.
19. The use as described in the above-mentioned 18, wherein ORL-1 receptor agonist
has an affinity of 1000 nmol/L or less IC50 value for ORL-1 receptor, and further inhibits cAMP elevation caused by a cAMP inducer
by 50% or more at a concentration of 1000 nmol/L or less.
20. The use as described in the above-mentioned 18, wherein ORL-1 receptor agonist
is a compound represented by the formula (I)

wherein each symbol is as defined above, a racemic mixture thereof, an enantiomer
corresponding thereto, or a pharmaceutically acceptable salt thereof.
Brief Description of the Drawings
[0012] Fig. 1 shows the results of an ORL-1 receptor binding test.
[0013] Fig. 2 shows the results of a cAMP assay.
[0014] Fig. 3 shows a typical example of a phase shift of a circadian rhythm in rats by
test compounds A, B and C, as ORL-1 receptor agonists.
[0015] Fig. 4 shows actions of a test compound D, an ORL-1 receptor antagonist on phase
advancing circadian rhythm in rats by test compounds A and B, as ORL-1 receptor agonists.
[0016] Fig. 5 shows actions of a test compound C as an ORL-1 receptor agonist on re-entrainment
after a 6-hour advancement of a light-dark cycle. A: shift of the light-dark cycle
and an administration timing, B: a typical example of a body-temperature rhythm re-entrainment,
and C: summary of results of 4 examples.
Detailed Description Of The Invention
[0017] An "ORL-1 receptor agonist" in the present invention refers to a compound having
an agonistic activity for an ORL-1 receptor. The ORL-1 receptor agonist is preferably
a compound having an affinity of 1000 nmol/L or less IC
50 value for the ORL-1 receptor, and further inhibits cAMP elevation caused by a cAMP
(cyclic adenosine monophosphate) inducer such as forskolin and isoproterenol by 50%
or more at a concentration of 1000 nmol/L or less. The present invention comprises
both of a full agonist and a partial agonist for the ORL-1 receptor.
[0018] Definitions of each symbol in the formula (I) are as follows. In the present specification,
the definitions apply irrespective of whether the terms appear alone or in a combination.
[0019] "Lower alkyl" means a straight or branched alkyl group containing 1 to 6 carbon atoms,
for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, tertiary
butyl, pentyl, hexyl and the like. Lower alkyl is preferably a straight or branched
alkyl group containing 1 to 4 carbon atoms.
[0020] "Lower alkenyl" means, straight or branched alkenyl containing 2 to 6 carbon atoms,
for example, vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl
and the like. Lower alkenyl is preferably a straight or branched alkenyl group containing
2 to 4 carbon atoms.
[0021] "Halogen" means chlorine, iodine, fluorine and bromine. Halogen is preferably fluorine.
[0022] "Lower alkoxy" means a straight or branched alkoxy group containing 1 to 6 carbon
atoms, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy and the like. Lower
alkoxy is preferably a straight or branched alkoxy group containing 1 to 4 carbon
atoms.
[0023] A "saturated nitrogen-containing hetero ring formed by binding with an adjacent nitrogen
atom", means a 5- or 6-membered ring which may further contain 1 to 3 heteroatoms
selected from a nitrogen atom, an oxygen atom and a sulfur atom, for example, piperidine,
pyrrolidine, morpholine, thiomorpholine, piperadine, methyl piperadine and the like.
Piperadine and morpholine are preferred.
[0024] "-C(O)-" means a carbonyl group.
[0025] "-S(O)-" means a sulfinyl group.
[0026] "-S(O)
2-" means a sulfonyl group.
[0027] A "pharmaceutically acceptable salt" comprises an acid-addition salt with an inorganic
acid and an organic acid such as chloric acid, oxalic acid, fumaric acid and the like,
and a salt with an inorganic base such as sodium, potassium, calcium, magnesium and
the like.
[0028] If the phenyl group and the saturated nitrogen-containing hetero ring formed by binding
with an adjacent nitrogen atom in the formula (I) are substituted with lower alkyl,
halogen, lower alkoxy, phenoxy or benzyloxy, the number of the substituent is preferably
1 to 3.
[0029] The compound is preferably a compound wherein R
1 is hydrogen, lower alkyl, -C(O)-lower alkyl, lower alkyl-carboxyl, lower alkyl-C(O)O-lower
alkyl or lower alkyl-C(O)NR
3R
4, or -S(O)
2-lower alkyl, R
2 is hydrogen or halogen, R
3 and R
4 are hydrogen or lower alkyl, or R
3 and R
4 bind with an adjacent nitrogen atom to form a saturated nitrogen-containing hetero
ring (the hetero ring may be substituted with lower alkyl, halogen, lower alkoxy,
phenoxy or benzyloxy), and X is O or S. Examples of preferred compound are as follows.
[1] (RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one,
[2] (RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-5-fluoro-2H-benzoimidazol-2-one,
[3] (RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-6-fluoro-2H-benzoimidazol-2-one,
[4] ethyl (RS)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetate,
[5] (RS)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetic
acid,
[6] (RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-3-(2-oxo-2-piperazin-1-ylethyl)-1,3-dihydro-2H-benzoimidazol-2-one
dihydrochloride,
[7] (RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-3-[2-(4-methylpiperazin-1-yl)-2-oxoethyl]-1,3-dihydro-2H-benzoimidazol-2-one
dihydrochloride,
[8] (RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-3-(2-morpholin-4-yl-2-oxoethyl)-1,3-dihydro-2H-benzoimidazol-2-one
hydrochloride,
[9] (RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazole-2-thione,
[10] (RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-3-methyl-2H-benzoimidazole-2-thione,
[11] (R)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one,
[12] (S)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one,
[13] (R)-3-acetyl-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one,
[14] (R)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-3-methanesulfonyl-1,3-dihydro-2H-benzoimidazol-2-one,
[15] ethyl (R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetate,
[16] (R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetic
acid,
[17] (R)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-3-(2-oxo-2-piperazin-1-ylethyl)-1,3-dihydro-2H-benzoimidazol-2-one
dihydrochloride,
[18] (R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}-N-methylacetamide,
[19] (R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}-N,N-dimethylacetamide,
and
[20] (R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetamide.
[0030] Particularly preferred compound is a compound wherein R
1 is hydrogen, -C(O)-lower alkyl or lower alkyl-C(O)NR
3R
4 (either R
3 or R
4 is hydrogen) or lower alkyl-C(O)NR
3R
4 (R
3 and R
4 bind with an adjacent nitrogen atom to form a saturated nitrogen-containing hetero
ring (the hetero ring may be substituted with lower alkyl, halogen, lower alkoxy,
phenoxy or benzyloxy)), R
2 is hydrogen and X is O. Examples of especially preferred compound are as follows.
(RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one,
(R)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one,
(S)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one,
(R)-3-acetyl-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one,
(R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}-N-methylacetamide,
and
(R)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-3-(2-oxo-2-piperadin-1-ylethyl)-1,3-dihydro-2H-benzoimidazol-2-one.
[0031] The compound of the formula (I) can be prepared, for example, by the following methods.
Method 1
[0032]

wherein each symbol is as defined above.
[0033] A compound of the formula (II) is reductively aminated by a compound of the formula
(III) to obtain a compound of the formula (I). The compound of the formula (II) and
the compound of the formula (III) are known compounds. The compound of the formula
(II) can be prepared by the method described in J. Chem. Soc., Perkin Trans 1, 1160,
1973, and the compound of the formula (III) can be prepared by the method described
in J. Med. Chem., 2001, 44, 3378.
[0034] Reductive amination of a keto compound of the formula (II) with amine such as the
compound of the formula (III) is described in J. Org. Chem., 55, 2552-54, 1990. The
present reaction according to this method is carried out by reacting ketone with amine
in the presence of Ti(IV)-isopropoxide and sodium cyanoborohydride in a solvent such
as tetrahydrofuran(THF), methanol or ethanol, or a mixture of suitable alcohol and
THF. The reaction temperature is about -78 to 100°C, and the reaction time is dozens
of minutes to 2 days.
Method 2
[0035]

wherein each symbol is as defined above.
[0036] The compound of the formula (I-1) wherein R
1 is hydrogen, is subjected to alkylation, alkenylation, phenylation, benzylation or
acylation to prepare a compound of the formula (I).
[0037] The compound of the formula (I-1) wherein R
1 is hydrogen, can be subjected to alkylation, alkenylation, phenylation, benzylation
or acylation according to a conventional method, for example, in the presence of corresponding
alkyl-halide, alkenyl-halide, benzyl-halide or acyl-halide such as methyl iodide,
allyl bromide, benzyl bromide, ethyl bromide, acetyl chloride and ethyl bromoacetate.
This reaction is carried out in the presence of metal hydride such as sodium hydride
at a temperature of about -78 to 100°C for a reaction time of dozens of minutes to
2 days.
Method 3
[0038]

wherein each symbol is as defined above.
[0039] The compound of the formula (IV) is treated with phenylene diamine represented by
the formula (V) to produce a compound of the formula (VI), which is cyclized to obtain
a compound of the formula (I-1) wherein R
1 is hydrogen.
[0040] Reductive amination of a keto compound of the formula (IV) with phenylene diamine
of the formula (V) is carried out in the presence of a metal hydride complex (for
example, sodium triacetoxy borohydride, sodium cyanoborohydride, sodium borohydride,
lithium borohydride and lithium aluminum hydride) in N,N-dimethylformamide, dimethylsulfoxide,
pyridine, dioxane, tetrahydrofuran, acetonitrile, chloroform, methylene chloride,
dichloroethane, methanol, ethanol, diethyl ether and the like, or a mixed solvent
thereof. The reaction temperature is about -78 to 100°C, and the reaction time is
dozens of minutes to 2 days. In addition, phenylene diamine of the formula (V) and
the keto compound of the formula (IV) are known compounds. For example, phenylene
diamine of the formula (V) can be prepared by the method described in J. Org. Chem.,
2001, 66, 919 or in Org. Synth., 1943, 501, and the keto compound of the formula (IV)
can be prepared by the method described in Bioorganic & Medicinal Chemistry Letters,
1999, 9, 2343.
[0041] The compound of the formula (VI) prepared in the present reaction can be carbonylated
or thiocarbonylated by a known method (See, Bioorganic & Medicinal Chemistry Letters,
1996, 6, 1641, Chem. Pharm. Bull., 1989, 37, 962, Bioorganic & Medicinal Chemistry
Letters, 1999, 9, 1537, etc.) to produce a compound of the formula (I-1).
Method 4
[0042]

wherein R
11 is lower alkyl-carboxyl and R
12 is lower alkyl-C(O)NR
3R
4. R
3, R
4 and X are as defined above.
[0043] A carbonic acid compound represented by the formula (I-2) or a reactive derivative
thereof is reacted with amine to obtain a compound of the formula (I-3). The reactive
derivative of a carbonic acid compound includes acid halide such as acid chloride,
acid anhydride, mixed acid anhydride formed from ethyl chloroformate and the like,
ester such as methyl ester and ethyl ester and a reactive derivative formed from carbodiimide
such as WSC·HCl (water soluble carbodiimide hydrochloride) and DCC (dicyclohexyl carbodiimide),
and the like. The reaction is carried out in an organic solvent such as N,N-dimethylformamide,
dimethylsulfoxide, dioxane, tetrahydrofuran, acetonitrile, chloroform, methylene chloride,
dichloroethane and toluene. The reaction temperature is about -78 to 100°C, and the
reaction time is dozens of minutes to 2 days. Further, if necessary, an organic base
such as pyridine, triethylamine and diisopropylethylamine is used as a deoxidizer.
[0044] Thus-synthesized compound of the formula (I) can be obtained as a racemate, and the
racemic mixture can be converted to an enantiomer component thereof to produce an
optically pure compound.
[0045] In addition, enantiomer of the compound of the formula (I) can be also produced by
using optically active materials.
[0046] If necessary, the obtained compound of the formula (I) is converted to a pharmaceutically
acceptable salt. The salt formation is per se known, and further carried out by well-known
method at room temperature. A salt with an organic acid is also considered as well
as salt with inorganic acid, and for a compound having a carboxyl group, salt with
inorganic base is also considered. Examples of such salt are an acid-addition salt
such as hydrochloride, oxalate and a fumarate, a sodium salt, a potassium salt, a
calcium salt, a magnesium salt and the like.
[0047] The ORL-1 receptor agonist which is an active ingredient of a preventive and/or therapeutic
agent for a sleep disorder of the present invention is not limited if it has agonistic
activity for the ORL-1 receptor, but is preferably a compound having an affinity of
1000 nmol/L or less IC
50 value for an ORL-1 receptor, and further inhibits cAMP elevation caused by a cAMP
inducer by 50% or more at a concentration of 1000 nmol/L or less. Examples of the
cAMP inducer include forskolin and isoproterenol.
[0048] The compound having an agonistic activity for the ORL-1 receptor is preferably the
compound of the formula (I), but also includes the compound having an agonistic activity
for the ORL-1 receptor among the piperidine compounds or the amide compounds disclosed
in publications such as JP-A-2000-26466, JP-A-11-228575, JP-A-10-212290, JP-A-2000-53686,
WO00/14067, WO99/29696, EP1122257, JP-A-2001-39974, WO00/08013, WO99/36421, EP0997464,
WO98/54168, WO00/31061, JP-A-2001-58991, WO01/39767, WO01/39775, WO02/085291, WO02/085354,
WO02/085355, WO02/085361, WO00/27815, WO00/06545, WO99/59997, WO99/48492, WO02/26714
and W003/000677. The "ORL-1 receptor agonist" in the present invention also includes
ORL-1 receptor agonist compounds described in these publications.
[0049] Among these, specific examples are (RS)-8-(acenaphthen-1-yl)-1-phenyl-1,3,8-triazaspiro[4.5]decan-4-one,
8-(decahydro-naphthalen-2-yl)-3-methyl-1-phenyl-1,3,8-triazaspiro[4.5]decan-4-one,
(1S,3aS)-8-(2,3,3a,4,5,6-hexahydro-1H-phenalene-1-yl)-1-phenyl-1,3,8-triazaspiro[4.5]decan-4-one,
1-(1-cyclooctylmethyl-4-piperidinyl)-2-(4-methylpiperadinyl)-1H-benzoimidazole and
the like though the chemical structure is not especially limited.
[0050] The effects of the present invention will be explained in detail in the section of
pharmacological tests below. The present inventors have investigated at first if compounds
having various chemical structures have an agonistic and/or antagonistic activity
for the ORL-1 receptor, and then have administered compounds having an agonistic or
antagonistic activity for the ORL-1 receptor to rats, and as results, they have found
that a compound having an ORL-1 receptor agonistic activity also showed the phase
advancing effect.
[0051] Since the present invention is characterized by the findings that an ORL-1 receptor
agonist shows the phase advancing effect regardless of the chemical structure, the
strength of their effects does not affect the usefulness of the present invention.
[0052] The sleep disorder which is the subject for the preventive and/or therapeutic agent
of the present invention includes, for example, a circadian rhythm sleep disorder
such as jet-lag syndromes, a shift-work sleep disorder, or delayed sleep phase syndromes.
The circadian rhythm sleep disorder also includes the disorder peculiar to the elders
(a geriatric circadian rhythm sleep disorder).
[0053] In addition, the preventive and/or therapeutic agent of the present invention can
be used suitably for a bright light therapy.
[0054] A compound having an ORL-1 receptor agonistic activity (an ORL-1 receptor agonist)
in the present invention can be administered orally or non-orally. Dosage form includes
tablet, capsule, granule, powder, injection, ointment, and suppository and the like.
These can be formulated by generally used techniques combining the ORL-1 receptor
agonist and various pharmaceutically acceptable additives (an excipient, a diluent,
a lubricant, a binder, a disintegrant, a coating agent, a filming agent, a base, a
solvent, etc.). For example, an oral formulation such as a tablet, a capsule, a granule
and a powder can be prepared using a diluent such as lactose, crystalline cellulose,
starch and vegetable oil, a lubricant such as magnesium stearate and talc, a binder
such as hydroxypropyl cellulose and polyvinyl pyrrolidone, a disintegrant such as
carboxymethyl cellulose calcium and low-substituted hydroxypropylmethyl cellulose,
a coating agent such as hydroxypropylmethylcellulose, macrogol and silicone resin,
a filming agent such as gelatin film, as desired. An ointment can be prepared using
a commonly used base such as white Vaseline and liquid paraffin.
[0055] The amount of an ORL-1 receptor agonist, an active ingredient in these formulations
is 0.1 to 100% by weight, suitably 1 to 50% by weight. In addition, the dose may be
suitably selected depending on symptoms, age, dosage form and the like. For the oral
formulation, the dose is usually 0.1 to 5000 mg, preferably, 1 to 1000 mg per day
and may be administered in a single dose or divided doses.
[0056] In addition, the present invention provides a commercial package comprising the above-described
preventive and/or therapeutic agent containing an ORL-1 receptor agonist, and a document
describing that the preventive and/or therapeutic agent can be or should be used for
preventing and/or treating a sleep disorder.
[0057] The results of Examples, Formulation Examples and Pharmacological Examples are shown
in the following. These are for better understanding of the present invention and
do not limit the scope of the present invention.
Example 1
(RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one
[0058]
(1) 1-Naphthylacetic acid (100 g, 530 mmol) was dissolved in dichloromethane (15 ml).
Thionyl chloride (158 g, 1.32 mol) was added under ice-cooling and the mixture was
heated under reflux for 1 hr. The solvent was evaporated and 1,2-dichloroethane (500
ml) was added to the obtained residue for dissolution. Aluminum chloride (150 g, 1.12
mol) was added under ice-cooling, and the mixture was stirred at room temperature
for 1 hr. The reaction mixture was poured into ice water, and the mixture was extracted
with dichloromethane. The extract was washed with water and saturated brine, dried
over magnesium sulfate and concentrated to give acenaphthen-1-one (80 g) as yellow
crystals.
1H-NMR(CDCl3)δTMS: 3.79(s, 2H), 7.43(d, J=6.8Hz, 1H), 7.57(t, J=6.8Hz, 1H), 7.68 (t, J=7.5Hz, 1H),
7.79(d, J=6.8Hz, 1H), 7.93(d, J=6.8Hz, 1H), 8.06 (d, J=6.8Hz, 1H) FAB-MS(M+H)+: 169
(2) Acenaphthen-1-one (1.68 g, 10 mmol) was dissolved in tetrahydrofuran (THF, 15
ml). 4-(2-Keto-1-benzoimidazolinyl)piperidine (2.17 g, 10 mmol) and tetraisopropyl
orthotitanate (3.4 g, 12 mmol) were added and the mixture was stirred at room temperature
for 20 hr. The solvent was evaporated and a mixed solvent (15 ml) of THF/ethanol (1:2)
was added to the obtained residue for dissolution. Sodium cyanoborohydrate (2.1 mmol)
was added to this solution, and the mixture was stirred at stirred at room temperature
for one day. Water was added, and the precipitate was removed by celite filtration
and washed with ethanol. The filtrate was extracted with chloroform and washed with
water and saturated brine. The extract was dried over sodium sulfate, and concentrated.
The obtained residue was purified by silica gel column chromatography (chloroform/methanol)
to give the title compound (0.68 g) as yellow crystals.
1H-NMR(CDCl3)δTMS: 1.74-1.82(m, 2H), 2.36-2.60(m, 4H), 2.81(m, 1H), 3.01(m, 1H), 3.42(d, J=5.6Hz, 2H),
4.29-4.36(m, 1H), 4.98(t, J=5.6Hz, 1H), 7.01(m, 3H), 7.28-7.31(m, 2H), 7.43-7.53(m,
3H), 7.60-7.62(m, 1H), 7.69(m, 1H), 9.77(brs, 1H)
FAB-MS (M+H)+: 370
Example 2
(RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-5-fluoro-2H-benzoimidazol-2-one
[0059] The title compound was obtained as pale-yellow crystals according to Example 1 and
using 4-(5-fluoro-2-keto-1-benzoimidazolinyl)piperidine.
1H-NMR(CDCl
3)δ
TMS: 1.72-1.85(m, 2H), 2.38-2.56(m, 4H), 2.86(m, 1H), 3.11(m, 1H), 3.42(d, J=5.6Hz, 2H),
4.30-4.36(m, 1H), 4.98(t, J=5.6Hz, 1H), 6.68(dd, J=13.2, 7.8Hz, 1H), 7.28-7.31(m,
2H), 7.46-7.53(m, 3H), 7.60(d, J=7.8Hz, 1H), 7.62(m, 1H), 7.69(m, 1H), 9.66(brs, 1H)
FAB-MS (M+H)
+: 388
Example 3
(RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-6-fluoro-2H-benzoimidazol-2-one
[0060] The title compound was obtained as pale-yellow crystals according to Example 1 and
using 4-(6-fluoro-2-keto-1-benzoimidazolinyl)piperidine.
1H-NMR(CDCl
3)δ
TMS: 1.72-1.86(m, 2H), 2.36-2.54(m, 4H), 2.88(m, 1H), 3.11(m, 1H), 3.42(d, J=5.6Hz, 2H),
4.32-4.38(m, 1H), 4.96(t, J=5.6Hz, 1H), 6.72(dd, J=13.2, 7.8Hz, 1H), 7.33-7.36(m,
2H), 7.46-7.53(m, 3H), 7.60(d, J=7.8Hz, 1H), 7.62(m, 1H), 7.69(m, 1H), 9.78 (brs,
1H)
FAB-MS (M+H)
+: 388
Example 4
Ethyl (RS)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetate
[0061] (RS)-1-[1-(Acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one (1.5
g, 4 mmol) was dissolved in dimethylformamide (DMF, 15 ml). Sodium hydride (200 mg,
60%) was added and the suspension was stirred at 50°C for 30 min. The mixture was
cooled to room temperature, ethyl bromoacetate (0.75 g, 4.5 mmol) was added and the
mixture was stirred for 1 hr. The reaction mixture was poured into water and the mixture
was extracted with ethyl acetate. The extract was washed with water and saturated
aqueous ammonium chloride solution, dried over magnesium sulfate, and concentrated.
The obtained residue was purified by silica gel column chromatography (chloroform/methanol)
to give the title compound (1.6 g) as pale-yellow crystals.
1H-NMR(CDCl
3)δ
TMS: 1.25(t, J=7.1, 3H), 1.82(m, 2H), 2.42-2.58 (m, 4H), 2.78(m, 1H), 3.03((m, 1H), 3.44(m,
2H), 4.22(q, J=7.1Hz, 2H), 4.35(m, 1H), 4.61(s, 2H), 5.01(m, 1H), 6.87(m, 1H), 7.05(m,
2H), 7.31(m, 2H), 7.45-7.55(m, 3H), 7.63(m, 1H), 7.71(m, 1H)
FAB-MS (M+H)
+: 456
Example 5
(RS)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetic
acid
[0062] Ethyl (RS)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetate
(1.6 g) was dissolved in ethanol (10 ml) and 2N-aqueous sodium hydroxide solution
(10 ml) was added. The mixture was stirred at room temperature for 30 min. The reaction
mixture was poured into water, thereto was added to 1N-hydrochloric acid for neutralization,
and the mixture was extracted with chloroform. The extract was washed with water and
saturated brine, dried over magnesium sulfate, and concentrated. The obtained solid
was washed with ethyl acetate to give the title compound (1.3 g) as pale-yellow crystals.
1H-NMR(DMSO-d
6)δ
TMS: 1.72-1.83(m, 2H) , 2.63-3.12 (m, 5H) , 3.30(m, 1H), 3.50-3.70(m, 2H), 4.49(m, 1H),
4.58(s, 2H), 5.36(m, 1H), 7.02-7.13(m, 2H), 7.14(d, J=6.8Hz, 1H), 7.40(d, J=6.8Hz,
1H), 7.52-7.65(m, 3H), 7.72(d, J=8.3Hz, 1H), 7.84(d, J=8.3Hz, 1H), 8.31(m, 1H), 11.55(brs,
1H)
FAB-MS(M+H)
+: 428
Example 6
(RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-3-(2-oxo-2-piperazin-1-ylethyl)-1,3-dihydro-2H-benzoimidazol-2-one
dihydrochloride
[0063]
(1) (RS)-2-{3-[1-(Acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetic
acid (0.85 g, 2 mmol) was dissolved in DMF (10 ml). Boc-piperazine (tert-butoxycarbonylpiperazine)
(0.37 g, 2 mmol), WSC·HCl (water soluble carbodiimide hydrochloric acid) (0.46 g,
2.4 mmol), HOBt (hydroxybenzotriazole) (0.37 g, 2.4 mmol) and triethylamine (0.53
ml, 3.8 mmol) were added and the mixture was stirred at room temperature for 10 hr.
The reaction mixture was poured into water, and the mixture was extracted with ethyl
acetate. The extract was washed with water and saturated aqueous ammonium chloride
solution, dried over magnesium sulfate, and concentrated. The obtained residue was
purified by silica gel column chromatography (chloroform/methanol) to give a yellow
solid (0.8 g).
(2) The above-mentioned yellow solid (0.8 g) was dissolved in 4N-hydrochloric acid/dioxane
(10 ml) and the mixture was stirred at room temperature for 1 hr. The solvent was
evaporated and isopropyl ether was added to the residue. The obtained crystals were
collected by filtration to give the title compound (0.5 g) as yellow crystals.
1H-NMR(DMSO-d6)δTMS: 1.76-1.88(m, 2H), 3.11-3.82(m, 15H), 3.96(m, 1H), 4.71(m, 1H), 4.83(s, 2H), 5.63(m,
1H), 7.02-7.12(m, 3H), 7.46(d, J=6.8Hz, 1H), 7.58(t, J=8.0Hz, 1H), 7.67(t, J=7.8Hz,
1H), 7.76-7.84(m, 2H), 7.92(m, 1H), 8.25(d, J=7.8Hz, 1H), 9.42(brs, 2H), 12.20(brs,
1H)
FAB-MS(M+H)+: 496
Example 7
(RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-3-[2-(4-methylpiperazin-1-yl)-2-oxoethyl]-1,3-dihydro-2H-benzoimidazol-2-one
dihydrochloride
[0064] (RS)-2-{3-[1-(Acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetic
acid (0.85 g, 2 mmol) was dissolved in DMF (10 ml). 1-Methylpiperazine (0.2 g, 2 mmol),
WSC·HCl (0.46 g, 2.4 mmol), HOBt (0.37 g, 2.4 mmol) and triethylamine (0.53 ml, 3.8
mmol) were added and the mixture was stirred at room temperature for 8 hr. The reaction
mixture was poured into water, and the mixture was extracted with ethyl acetate. The
extract was washed with water and saturated aqueous ammonium chloride solution, dried
over magnesium sulfate, and concentrated. The obtained residue was purified by silica
gel column chromatography (chloroform/methanol) and hydrochloric acid/ethanol was
added to give the title compound (0.73 g) as a yellow solid.
1H-NMR(DMSO-d
6)δ
TMS: 1.76-1.89(m, 2H), 2.77-3.74(m, 16H), 3.96(m, 1H), 4.16(m, 1H), 4.31(m, 1H), 4.71(m,
1H), 4.76(d, J=17.3Hz, 1H), 4.92(d, J=17.3Hz, 1H), 5.63(m, 1H), 7.02-7.09(m, 3H),
7.45-7.55(m, 1H), 7.56-7.65(m, 1H), 7.67-7.69(m, 1H), 7.76-7.82(m, 2H), 7.91-7.94(m,
1H), 8.25(m, 1H), 11.32(brs, 1H), 12.23(brs, 1H)
FAB-MS (M+H)
+: 510
Example 8
(RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-3-(2-morpholin-4-yl-2-oxoethyl)-1,3-dihydro-2H-benzoimidazol-2-one
hydrochloride
[0065] The title compound was obtained as pale-yellow crystals according to Example 7 and
using morpholine.
1H-NMR(DMSO-d
6)δ
TMS: 1.78-1.89 (m, 2H), 2.83(m, 1H), 3.05(m, 2H), 3.31-3.76(m, 12H), 3.95(m, 1H), 4.69(m,
1H), 4.76(s, 2H), 5.63(m, 1H), 7.02-7.08(m, 3H), 7.45-7.47(m, 1H), 7.56-7.60(m, 1H),
7.66-7.78(m, 3H), 7.92-7.94(m, 1H), 8.18(m, 1H), 11.85(brs, 1H)
FAB-MS(M+H)
+: 497
Example 9
(RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazole-2-thione
[0066]
(1) Acenaphthen-1-one (34 g, 200 mmol) was dissolved in methanol (300 ml). Sodium
borohydride (8 g, 200 mmol) was added to this solution under ice-cooling, and the
mixture was stirred at room temperature for 1 hr. The reaction mixture was poured
into water, and the mixture was extracted with ethyl acetate. The extract was washed
with water and saturated brine, dried over magnesium sulfate, and concentrated to
give 1-acenaphthenol (33 g) as yellow crystals.
(2) To a solution of 1-acenaphthenol (33 g, 190 mmol) and diphenylphosphorylazide
(63 g, 230 mmol) in toluene (300 ml) was cooled to 0°C, DBU (diazabicycloundecene)
(35 g, 230 mmol) was added and the mixture was stirred at room temperature for 6 hr.
The reaction mixture was poured into water and extracted with toluene. The combined
organic phase was washed with water, dried over magnesium sulfate, and concentrated.
A crude product was dissolved in a mixed solvent (330 ml) of THF/water (10:1), triphenylphosphine
(53 g) was added thereto, and the mixture was heated under reflux for 6 hr. After
cooling to room temperature, the solvent was evaporated and 1N-hydrochloric acid (200
ml) was added to the residue. Unnecessary materials were extracted with ethyl acetate.
The aqueous phase was alkalified with potassium carbonate and extracted with chloroform.
The extract was washed with water and saturated brine, dried over magnesium sulfate,
and concentrated to give acenaphthen-1-yl-amine (20 g) as a red oil.
(3) Acenaphthen-1-yl-amine (20 g, 118 mmol) was dissolved in ethanol (200 ml). Potassium
carbonate (1.7 g, 12 mmol) and 1-ethyl-1-methyl-4-oxopiperidinium iodide (38 g) dissolved
in water (100 ml) was added and the mixture was heated under reflux for 1 hr. The
reaction mixture was poured into water, and the mixture was extracted with ethyl acetate.
The extract was washed with water and saturated brine, dried over magnesium sulfate,
and concentrated. The obtained residue was purified by silica gel column chromatography
(chloroform/methanol) to give 1-(acenaphthen-1-yl)-piperidin-4-one (23 g) as yellow
crystals.
(4) To a solution of 1-(acenaphthen-1-yl)-piperidin-4-one (12 g, 48 mmol) and 1,2-phenylenediamine
(10.8 g, 100 mmol) in THF (100 ml) was cooled to 0°C were added sodium triacetoxy
borohydride (34 g) and acetic acid (12 ml) and the mixture was stirred at room temperature
for 17 hr. The reaction mixture was poured into water and potassium carbonate was
added for neutralization. The mixture was extracted with ethyl acetate. The extract
was washed with water and saturated brine, dried over sodium sulfate, and concentrated.
The obtained residue was purified by silica gel column chromatography (chloroform/methanol)
to give N-[1-(acenaphthen-1-yl)piperidin-4-yl]-benzene-1,2-diamine (8.5 g) as yellow
crystals.
(5) N-[1-(Acenaphthen-1-yl)piperidin-4-yl]-benzene-1,2-diamine (1 g, 3 mmol) was dissolved
in THF (30 ml), and triethylamine (1.4 ml, 10 mmol) and 1,1'-thiocarbonyldiimidazole
(0.63 g, 3.5 mmol) were added. The mixture was stirred at room temperature for 3 hr.
The reaction mixture was poured into water, and the mixture was extracted with ethyl
acetate. The extract was washed with water and saturated aqueous ammonium chloride
solution, dried over magnesium sulfate, and concentrated. The obtained residue was
purified by silica gel column chromatography (chloroform/methanol) to give the title
compound (1.17 g) as a gray-white solid.
1H-NMR(CDCl3)δTMS: 1.85(m, 2H), 2.42-2.55(m, 3H), 2.63(m, 1H), 2.82(m, 1H), 3.04(m, 1H), 3.44(d, J=5.6Hz,
2H), 4.98(t, J=5.6Hz, 1H), 5.19(m, 1H), 7.15-7.24(m, 3H), 7.29(m, 1H), 7.45(m, 1H),
7.50-7.63(m, 4H), 7.68(m, 1H), 9.62(brs, 1H)
FAB-MS(M+H)+: 386
Example 10
(RS)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-3-methyl-2H-benzoimidazole-2-thione
[0067] (RS)-1-[1-(Acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazole-2-thione
(1 g, 2.6 mmol) was dissolved in DMF (15 ml) and sodium hydride (120 mg, 60%) was
added. The suspension was stirred at 50°C for 30 min. After cooling to room temperature,
methyl iodide (0.4 g, 2.8 mmol) was added and the mixture was stirred for 1 hr. The
reaction mixture was poured into water, and the mixture was extracted with ethyl acetate.
The extract was washed with water and saturated aqueous ammonium chloride solution,
dried over magnesium sulfate, and concentrated. The obtained residue was purified
by silica gel column chromatography (chloroform/methanol) to give the title compound
(1.05 g) as pale-yellow crystals.
1H-NMR(CDCl
3)δ
TMS: 1.83(m, 2H), 2.38(m, 1H), 2.51-2.64(m, 3H), 2.78(s, 3H), 2.83(m, 1H), 3.05(m, 1H),
3.45(d, J=5.6Hz, 2H), 4.15(m, 1H), 5.01(t, J=5. 6Hz, 1H), 7.15-7.21 (m, 2H), 7.31(m,
1H), 7.47(m, 1H), 7.54-7.73 (m, 6H)
FAB-MS(M+H)
+: 400
Example 11
(R)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one
[0068]
(1) (R)-2-Methyl-CBS-oxazaboro-lidine (50 ml, 1 mol toluene solution) was cooled to
-30°C, and a borane·THF complex (250 ml, 1 mol THF solution) was added. The mixture
was stirred for 45 min. Acenaphthen-1-one (40 g, 240 mmol) was dissolved in dichloromethane
(500 ml) and the solution was added dropwise. The mixture was stirred under cooling
(-30°C) for 2 hr. Then, methanol (80 ml) and 1N-hydrochloric acid (100 ml) were added
under ice-cooling, and the mixture was extracted with ethyl acetate. The extract was
washed with water and saturated aqueous ammonium chloride solution, dried over magnesium
sulfate, and concentrated to give (S)-1-acenaphthenol (35 g) as pale-yellow crystals.
1H-NMR(CDCl3)δTMS: 1.96(brs, 1H) , 3.24(d, J=17.5Hz, 1H) , 3. 80 (dd, J=17.5, 7.5Hz, 1H), 5.73(m, 1H),
7.30(d, J=6.8Hz, 1H), 7.48(t, J=6.8Hz, 1H), 7.53-7.56(m, 2H), 7.64(d, J=7.5Hz, 1H),
7.75(m, 1H)
FAB-MS(M+H)+: 171
[α]D20 =1. 93
(2) A solution of (S)-1-acenaphthenol (35 g, 200 mmol) and diphenylphosphorylazide
(66 g, 240 mmol) in toluene (300 ml) was cooled to 0°C and DBU (36 g, 240 mmol) was
added. The mixture was stirred at room temperature for 6 hr. The reaction mixture
was poured into water, and extracted with toluene. The combined organic phase was
washed with water, dried over magnesium sulfate, and concentrated. The crude product
was dissolved in a mixed solvent (220 ml) of THF/water (10:1) and triphenylphosphine
(40 g) was added. The mixture was heated under reflux for 6 hr. After cooling to room
temperature, the solvent was evaporated and 1N-hydrochloric acid (200 ml) was added
to the residue. Unnecessary materials were removed by extraction with ethyl acetate.
The aqueous phase was alkalified with potassium carbonate and extracted with chloroform.
The extract was washed with water and saturated brine, dried over magnesium sulfate,
and concentrated. Hydrochloric acid/ethanol was added to the obtained red oil to give
(R)-acenaphthen-1-yl-amine·hydrochloride (25 g) as yellow crystals.
1H-NMR(DMSO-d6)δTMS: 3.32(d, J=17.3Hz, 1H), 3.82(dd, J=17.3, 8.1Hz, 1H), 5.20(m, 1H), 7.40(d, J=6.8Hz,
1H), 7.48(t, J=6.8Hz, 1H), 7.55-7.62(m, 2H), 7.73(d, J=8.1Hz, 1H), 7.85(d, J=7.8Hz,
1H), 8.9 (brs, 3H)
FAB-MS(M+H)+: 170
(3) (R)-Acenaphthen-1-yl-amine*hydrochloride (25 g) was dissolved in water (200 ml)
and the mixture was alkalified with potassium carbonate and extracted with chloroform.
The extract was washed with water and saturated brine, dried over magnesium sulfate,
and concentrated. The obtained (R)-acenaphthen-1-yl-amine (21 g, 124 mmol) was dissolved
in ethanol (200 ml). Potassium carbonate (2.5 g, 18 mmol) and 1-ethyl-1-methyl-4-oxopiperidinium
iodide (40 g) dissolved in water (100 ml) was added and the mixture was heated under
reflux for 2 hr. The reaction mixture was poured into water, and the mixture was extracted
with ethyl acetate. The extract was washed with water and saturated brine, dried over
magnesium sulfate, and concentrated. The obtained residue was purified by silica gel
column chromatography (chloroform/methanol) to give (R)-1-(acenaphthen-1-yl)-piperidin-4-one
(22 g) as a red-yellow oil.
(4) A solution of (R)-1-(acenaphthen-1-yl)-piperidin-4-one (12.6 g, 50 mmol) and 1,2-phenylenediamine
(10.8 g, 100 mmol) in THF (100 ml) was cooled to (0°C), sodium triacetoxy borohydride
(30 g) and acetic acid (12 ml) were added thereto, and the mixture was stirred at
room temperature for 24 hr. The reaction mixture was poured into water, and potassium
carbonate was added for neutralization. The mixture was extracted with ethyl acetate.
The extract was washed with water and saturated brine, dried over sodium sulfate,
and concentrated. The obtained residue was purified by silica gel column chromatography
(chloroform/methanol) to give (R)-N-[1-(acenaphthen-1-yl)piperidin-4-yl]-benzene-1,2-diamine
(9 g) as yellow crystals.
(5) (R)-N-[1-(Acenaphthen-1-yl)piperidin-4-yl]-benzene-1,2-diamine (9 g, 26 mmol)
was dissolved in THF (100 ml), and carbonyldiimidazole (5 g, 30 mmol) was added. The
mixture was stirred at room temperature for 2 hr. The reaction mixture was poured
into water', and the mixture was extracted with ethyl acetate. The extract was washed
with water and saturated aqueous ammonium chloride solution, dried over magnesium
sulfate, and concentrated. The obtained residue was purified by silica gel column
chromatography (chloroform/methanol) to give the title compound (8.8 g) as a white
solid.
1H-NMR(CDCl3)δTMS: 1.74-1.82(m, 2H), 2.36-2.60(m, 4H), 2.81(m, 1H), 3.01(m, 1H), 3.42(d, J=5.6Hz, 2H),
4.29-4.36(m, 1H), 4.98(t, J=5.6Hz, 1H), 7.01(m, 3H), 7.28-7.31(m, 2H), 7.43-7.53(m,
3H), 7.60-7.62(m, 1H), 7.69(m, 1H), 9.56(brs, 1H)
FAB-MS (M+H)+: 370
[α]D20 =52.5°
Example 12
(S)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one
[0069] The title compound was obtained as white crystals according to Example 11 and using
(S)-2-methyl-CBS-oxazaborolidine (1 mol toluene solution).
1H-NMR(CDCl
3)δ
TMS: 1.74-1.82(m, 2H), 2.36-2.60(m, 4H), 2.81(m, 1H), 3.01(m, 1H), 3.42(d, J=5.6Hz, 2H),
4.29-4.36(m, 1H), 4.98(t, J=5.6Hz, 1H), 7.01(m, 3H), 7.28-7.31(m, 2H), 7.43-7.53(m,
3H), 7.60-7.62(m, 1H), 7.69(m, 1H), 9.67(brs, 1H)
FAB-MS(M+H)
+: 370
[α]
D20=-52.6°
Example 13
(R)-3-acetyl-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one
[0070] (R)-1-[1-(Acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one (6.2
g, 16.8 mmol) was dissolved in DMF (60 ml). Sodium hydride (0.9 g, 60%) was added
and the suspension was stirred at 50°C for 30 min. It was cooled to room temperature
and acetyl chloride (1.5 g, 19 mmol) was added and the mixture was stirred for 3 hr.
The reaction mixture was poured into water and the mixture was extracted with ethyl
acetate. The extract was washed with water and saturated aqueous ammonium chloride
solution, dried over magnesium sulfate, and concentrated. The obtained residue was
purified by silica gel column chromatography (chloroform/methanol) to give the title'
compound (6.3 g) as pale-yellow crystals
1H-NMR(CDCl
3)δ
TMS: 1.68-1.81(m, 2H), 2.40-2.56(m, 4H), 2.74(s, 3H), 2.78(m, 1H), 3.02(m, 1H), 3.42(m,
2H), 4.30(m, 1H), 4.98(m, 1H), 7.11-7.31(m, 4H), 7.45-7.71 (m, 5H), 8.24(m, 1H)
FAB-MS (M+H)
+: 412
[α]
D20=40.1°
Example 14
(R)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-3-methanesulfonyl-1,3-dihydro-2H-benzoimidazol-2-one
[0071] The title compound was obtained as pale-yellow crystals according to Example 13 and
using methanesulfonyl chloride.
1H-NMR(CDCl
3)δ
TMS: 1.71-1.85 (m, 2H), 2.40-2.58(m, 4H), 2.85(s, 3H), 2.75(m, 1H), 3.02(m, 1H), 3.45(m,
2H), 4.28(m, 1H), 5.01(m, 1H), 7.1-7.31(m, 4H), 7.46-7.68(m, 5H), 8.28(m, 1H)
FAB-MS(M+H)
+: 448
[α]
D20=43.8°
Example 15
Ethyl (R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetate
[0072] (R)-1-[1-(Acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one (2.3
g, 6 mmol) was dissolved in DMF (20 ml) and sodium hydride (300 mg, 60%) was added.
The suspension was stirred at 50°C for 30 min. After cooling to room temperature,
ethyl bromoacetate (1.17 g, 7 mmol) was added and the mixture was stirred for 2 hr.
The reaction mixture was poured into water, and the mixture was extracted with ethyl
acetate. The extract was washed with water and saturated aqueous ammonium chloride
solution, dried over magnesium sulfate, and concentrated. The obtained residue was
purified by silica gel column chromatography (chloroform/methanol) to give the title
compound (2.6 g) as pale-yellow crystals.
1H-NMR(CDCl
3)δ
TMS: 1.26(t, J=7.1, 3H), 1.82(m, 2H), 2.40-2.56(m, 4H), 2.78(m, 1H), 3.01((m, 1H), 3.44(m,
2H), 4.21(q, J=7.1Hz, 2H), 4.35(m, 1H), 4.61(s, 2H), 4.99(m, 1H), 6.87(m, 1H) , 7.07(m,
2H), 7.31(m, 2H), 7.45-7.55(m, 3H), 7.63(m, 1H), 7.71(m, 1H)
FAB-MS (M+H)
+: 456
[α]
D20=40.2°
Example 16
(R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetic
acid
[0073] Ethyl (R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetate
(2.6 g, 5.8 mmol) was dissolved in ethanol (10 ml), 2N-aqueous sodium hydroxide solution
(10 ml) was added and the mixture was stirred at room temperature for 2 hr. The reaction
mixture was poured into water, 1N-hydrochloric acid was added for neutralization,
and the mixture was extracted with chloroform. The extract was washed with water and
saturated brine, dried over magnesium sulfate, and concentrated. The obtained solid
was washed with ethyl acetate to give the title compound (2.4 g) as pale-yellow crystals.
1H-NMR(DMSO-d
6)δ
TMS: 1.71-1.83 (m, 2H), 2.63-3.10(m, 5H) , 3.30(m, 1H), 3.58-3.70(m, 2H), 4.49(m, 1H),
4.58(s, 2H), 5.36(m, 1H), 7.02-7.13(m, 2H), 7.14(d, J=6.8Hz, 1H), 7.40(d, J=6.8Hz,
1H), 7.52-7.65(m, 3H), 7.72(d, J=8.3Hz, 1H), 7.84(d, J=8.3Hz, 1H), 8.31(m, 1H), 12.08(brs,
1H)
FAB-MS(M+H)
+:428
[α]
D20=42.5°
Example 17
(R)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-3-(2-oxo-2-piperazin-1-ylethyl)-1,3-dihydro-2H-benzoimidazol-2-one
dihydrochloride
[0074]
(1) (R)-2-{3-[1-(Acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetic
acid (1.28 g, 3 mmol) was dissolved in DMF (15 ml). Boc-piperazine (0.56 g, 3 mmol),
WSC·HCl (0.7 g, 3.6 mmol), HOBt (0.55 g, 2.4 mmol) and triethylamine (0.8 ml, 5.7
mmol) were added and the mixture was stirred at room temperature for 10 hr. The reaction
mixture was poured into water, and the mixture was extracted with ethyl acetate. The
extract was washed with water and saturated aqueous ammonium chloride solution, dried
over magnesium sulfate, and concentrated. The obtained residue was purified by silica
gel column chromatography (chloroform/methanol) to give a yellow solid (1.2 g).
(2) The above-mentioned compound was dissolved in 4N-hydrochloric acid/dioxane (10
ml) and the mixture was stirred at room temperature for 2 hr. The solvent was evaporated
and isopropyl ether was added to the residue. The obtained crystals were collected
by filtration to give the title compound (0.8 g) as yellow crystals.
1H-NMR(DMSO-d6)δTMS: 1.76-1.88(m, 2H), 3.11-3.82 (m, 15H) , 3.96(m, 1H), 4.71(m, 1H), 4.83(s, 2H), 5.63
(m, 1H), 7.02-7.12 (m, 3H), 7.46(d, J=6.8Hz, 1H), 7.58(t, J=8.0Hz, 1H), 7.67(t, J=7.8Hz,
1H), 7.76-7.84 (m, 2H) , 7.92 (m, 1H), 8.25(d, J=7.8Hz, 1H), 9.58(brs,
2H), 12.28(brs, 1H)
FAB-MS (M+H)+:496
[α]D20=48.5°
Example 18
(R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}-N-methylacetamide
[0075] (R)-2-{3-[1-(Acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl)acetic
acid (1 g, 2.3 mmol) was dissolved in DMF (10 ml). Methylamine hydrochloride (0.17
g, 2.5 mmol), WSC·HCl (0.53 g, 2.7 mmol), HOBt (0.43 g, 2.8 mmol) and triethylamine
(0.7 ml, 5 mmol) were added and the mixture was stirred at room temperature for 15
hr. The reaction mixture was poured into water, and the mixture was extracted with
ethyl acetate. The extract was washed with water and saturated aqueous ammonium chloride
solution, dried over magnesium sulfate, and concentrated. The obtained residue was
purified by silica gel column chromatography (chloroform/methanol) to give the title
compound (0.7 g) as pale-yellow crystals.
1H-NMR(DMSO-d
6)δ
TMS: 1.59-1.70(m, 2H) , 2.28-2.49 (m, 4H) , 2. 58 (s, 3H), 2.95(m, 1H), 3.35-3.43(m,
3H), 4.16(m, 1H), 4.40(s, 2H), 4.96(m, 1H), 7.02(m, 3H), 7.28-7.33(m, 1H), 7.45-7.57(m,
3H), 7.65(d, J=8.3Hz, 1H), 7.72(d, J=7.8Hz, 1H), 8.08(m, 1H)
FAB-MS (M+H)
+: 441
[α]
D20=43.2°
Example 19
(R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl)-N,N-dimethylacetamide
[0076] The title compound was obtained as pale-yellow crystals according to Example 18 and
using dimethylamine hydrochloride.
1.76-
1H-NMR(CDCl
3)δ
TMS: 1. 84 (m, 2H) , 2.40-2.55 (m, 4H) , 2.78 (m, 1H), 2.96(s, 3H), 3.01(m, 1H), 3.12(s,
3H), 3.45(m, 2H), 4.35(m, 1H), 4.66(s, 2H), 5.00(m, 1H), 6.99-7.07(m, 3H), 7.30(m,
2H), 7.45-7.70(m, 5H)
FAB-MS (M+H)
+: 455
[α]
D20=39.7°
Example 20
(R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetamide
[0077] (R)-2-{3-[1-(Acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}acetic
acid (400 mg, 0.9 mmol) was dissolved in dichloromethane (10 ml). Thionyl chloride
(0.2 ml, 2.7 mmol) was added under ice-cooling, and the mixture was stirred at room
temperature for 2 hr. The solvent was evaporated and aqueous ammonia (5 ml) was added
to the obtained residue under ice-cooling, and the mixture was further stirred under
ice-cooling. The precipitated crystals were collected by filtration to give the title
compound (0.22 g) as pale-yellow crystals.
1H-NMR(DMSO-d
6)δ
TMS: 1.62-1.70(m, 2H), 2.31-2.51(m, 4H), 2.61(m, 1H), 2.97(m, 1H), 3.38(m, 2H), 4.18(m,
1H), 4.39(s, 2H), 4.97(m, 1H), 7.00-7.05(m, 3H), 7.22-7.33(m, 3H), 7.45-7.73(m, 6H)
FAB-MS (M+H)
+:427
[α]
D20=45°
Formulation Example 1: tablet
[0078]
| compound of the present invention |
10.0 mg |
| lactose |
50.0 mg |
| corn starch |
20.0 mg |
| crystalline cellulose |
29.7 mg |
| polyvinylpyrrolidone K30 |
5.0 mg |
| talc |
5.0 mg |
| magnesium stearate |
0.3 mg |
| |
120.0 mg |
[0079] The compound of the present invention, lactose, corn starch and crystalline cellulose
were mixed, kneaded with polyvinylpyrrolidone K30 paste solution, and granulated by
passing a 20 mesh sieve. After drying at 50°C for 2 hr, the granules were passed through
a 24 mesh sieve, talc and magnesium stearate were admixed and tablets (120 mg per
tablet) were produced using a pounder having a diameter of 7 mm.
Formulation Example 2: capsule
[0080]
| compound of the present invention |
10.0 mg |
| lactose |
70.0 mg |
| corn starch |
35.0 mg |
| polyvinylpyrrolidone K30 |
2.0 mg |
| talc |
2.7 mg |
| magnesium stearate |
0.3 mg |
| |
120.0 mg |
[0081] The compound of the present invention, lactose, corn starch and crystalline cellulose
were mixed, kneaded with polyvinylpyrrolidone K30 paste solution, and granulated by
passing a 20 mesh sieve. After drying at 50°C for 2 hr, the granules were passed through
a 24 mesh sieve, admixed with talc and magnesium stearate and the mixture was filled
in a hard capsule (No. 4) to give capsules (120 mg).
[0082] The test results in the following shows that the ORL-1 receptor agonist is useful
for preventing and/or treating a sleep disorder, for example, a circadian rhythm sleep
disorder such as jet-lag syndromes, a shift-work sleep disorder or delayed sleep phase
syndromes.
[0083] Hereinbelow, pharmacological actions of the medicament of the present invention will
be explained by Experimental Examples.
[0084] As the test compounds, the following 4 kinds of compounds were used.
compound A: (RS)-8-(acenaphthen-1-yl)-1-phenyl-1,3,8-triazaspiro[4.5]decan-4-one (synthesized
according to the method described in Bioorganic & Medicinal Chemistry Letters, 1999,
9, 2343)
compound B: (R)-1-[1-(acenaphthen-1-yl)piperidin-4-yl]-1,3-dihydro-2H-benzoimidazol-2-one
(compound of Example 11) compound C: (R)-2-{3-[1-(acenaphthen-1-yl)piperidin-4-yl]-2,3-dihydro-2-oxo-benzoimidazol-1-yl}-N-methylacetamide
(compound of Example 18)
compound D: N-(4-amino-2-methylquinolin-6-yl)-2-(4-ethylphenoxymethyl)benzamide hydrochloride
(synthesized according to the method described in JTC-801, J. Med. Chem. 2000, 43,
4667)
Experimental Example 1: ORL-1 receptor binding test
Experimental Method and Measurement
[0085] Binding test of [
3H]-nociceptin was carried out using a standard product of the receptor prepared from
cerebral cortex of rat. Specifically, 50 µl of a test substance solution of each concentration,
900 µl of a solution of the receptor standard product, and 50 µl of a labeled ligand
[
3H]-nociceptin were added to a polypropylene tube successively, and were subjected
to reaction at 25°C for 20 minutes. The reaction solution was sucking-filtered with
Whatman GF/B, glass filter in a cell harvester. The filter was three times washed
with an ice-cooled, 50mmol/l Tris/chloric acid buffer solution, and put into a measurement
vial. ACS-II (2 ml, Amersham Pharmacia Biotech), liquid scintillation cocktail was
added, and then the radioactivity was measured using a liquid scintillation counter
(LSC-5100, ALOKA CO., LTD.). A non-labeled ligand test compound A was used to obtain
the amount of non-specific binding. Binding inhibition (%) and inhibition constant
(Ki value) were calculated according to the following calculation formulae.

N: Amount of non-specific binding, T: Amount of total binding, B: Amount of binding
in the presence of test substance

IC
50: 50% Inhibition concentration, L: Concentration of a labeled ligand, Kd: Dissociation
constant of a labeled ligand
Results and Discussion
[0086] As shown in Fig. 1, test compounds A, B, C and D inhibited the binding of [
3H]-nociceptin, depending on a concentration, and the IC
50 values were 84.2, 72.8, 4.4, 500 nmol/L, respectively. In addition, Ki values were
10.0, 8.4, 0.51 and 60.6 nmol/L, respectively.
[0087] From the above results, it was obvious that any one of test compounds A, B, C and
D had affinity for an ORL-1 receptor.
Experimental Example 2: Agonist action
Experimental Method and Measurement
[0088] ORL-1 receptor agonistic activity was measured using HEK293 cells which strongly
expressed a human ORL-1 receptor by the index of inhibiting activity for CAMP elevation
by forskolin stimulation. In other words, cells expressing a human ORL-1 receptor
was incubated overnight using a collagen-coated 96-well microplate, the incubation
solution was discarded, and 100 µl of a Krebs-Ringer solution was added. Then, 50
µl of a test substance solution of each concentration was added, and was preincubated
at 37°C for 5 minutes. Further, 50 µl of a forskolin solution (1 µmol/L of a final
concentration) was added and incubated at 37°C for 15 minutes. After discarding the
supernatant, 200 µl of a cell solubilizer was added to obtain a sample for cAMP assay
in cells. CAMP concentration in the sample for CAMP assay was measured with BIOTRAK
(Amersham Pharmacia Biotech), a kit for CAMP assay.
Results and Discussion
[0089] As shown in Fig. 2, the test compounds A, B and C inhibited cAMP production depending
on concentration. Therefore, it was obvious that the test compounds A, B and C had
ORL-1 receptor agonistic activity. On the other hand, the test compound D did not
inhibit cAMP production though it showed affinity for an ORL-1 receptor. In other
words, it was obvious that the test compound D was ORL-1 receptor antagonist.
Experimental Example 3: Phase shift of circadian rhythm by the ORL-1 receptor agonist under a constant dark
condition
Experimental Method and Measurement
[0090] The rats which had been previously subject to surgery to implant transmitter for
measuring body temperature and activity (TA10TA-F20) in the peritoneal cavity, was
used in this experiment. After a certain recovery period, the rats were put into a
soundproof box having equipped with a signal-receiving board, and were raised individually
under a constant dark condition. The body temperature and the activity of rats were
measured automatically with a telemetry auto-measuring system every 5 minutes, and
the results of the measurement were stored in a computer. The body-temperature rhythm
was indicated by plotting time in horizontal axis, and days in vertical axis and temperatures
higher than a mean body-temperature calculated by a least squares method were represented
in a black line. After confirming that the body-temperature rhythm was recorded to
be stable for 10 days or longer for a constant period, the ORL-1 receptor agonist
was administered intraperitoneally every 3 hour at various times (CT0, CT3, CT6, CT9,
CT12, CT15, CT18 and CT21 (CT: circadian time); the initiation time of body-temperature
elevation under a constant dark condition was set to be CT12, and 1 day was represented
as CT0 to CT24), to investigate for any phase shifts.
Results and Discussion
[0091] Fig. 3 shows typical examples of a circadian rhythm phase shift when the test compounds
A, B and C were administered at CT6. All of the test compounds A, B and C, which are
ORL-1 receptors, showed a noticeable phase advancing action when administered at CT6
or CT9.
Experimental Example 4: Antagonistic action of the ORL-1 receptor antagonist on the phase advancement by
the ORL-1 receptor agonist
Experimental Method and Measurement
[0092] The test compound D as an ORL-1 receptor antagonist was administered orally 1 hour
before the test compound A or B was administered under the same constant dark condition
as in Experimental Example 3, to investigate any phase shifts. The test compound A
or B was administered intraperitoneally at CT6 when the most noticeable phase advancement
was observed in Experimental Example 3.
Results and Discussion
[0093] Fig. 4 shows the results of the action of the test compound D as an ORL-1 receptor
antagonist, on the phase advancement by the test compounds A and B. The phase advancement
by the ORL-1 receptor agonist, any of the test compounds A and B was antagonized by
pre-administration of the test compound D, as an ORL-1 receptor antagonist. Therefore,
the phase advancement by the test compounds A and B was considered as a reaction via
the ORL-1 receptor. In addition, it was obvious that the ORL-1 receptor antagonist
showed no phase shift from the fact that no phase shift was observed for the test
compound D alone.
Experimental Example 5: Action of the ORL-1 receptor agonist on re-entrainment of a light-dark cycle
Experimental Method and Measurement
[0094] Rats were raised for 10 days or longer with a light-dark cycle of 12 hours (illumination
in a light period; 150 lux). After confirming that body-temperature is recorded to
be stably changed in a day, the light-dark cycle was advanced by 6 hours by advancing
the initiation time of the light period by 6 hours. By a phase response curve obtained
under a constant dark condition, the test substance C was administered at the administration
time when the ORL-1 receptor agonist showed most phase advancing effect, namely, ZT6
(ZT: zeitgeber time, the initiation time of the light period was set to be ZT0, and
1 day was represented as ZT0 to ZT24), to investigate the influence on re-entrainment.
Results and Discussion
[0095] Fig. 5 shows the results of the effect of test compound C on re-entrainment after
a 6-hour advancement of the light-dark cycle. The time required for re-entrainment
to a new light-dark cycle was 1 week or more for the vehicle-administered group. However,
the test compound C-administered group was almost re-entrained to a new light-dark
cycle in about 3 days after the advancement of the light-dark cycle. In other words,
the ORL-1 receptor agonist showed effectiveness for an artificially prepared jet-lag
model.
Industrial Applicability
[0096] From the above-described pharmacological experiments, a medicament containing the
ORL-1 receptor agonist, is useful for preventing and/or treating a sleep disorder,
for example, a circadian rhythm sleep disorder such as jet-lag syndromes, a shift-work
sleep disorder or delayed sleep phase syndromes.
[0097] This application is based on a patent application No. 2002-93398 filed in Japan,
the contents of which are hereby incorporated by reference.